The release last month of the Better Together update for Minecraft brought together Minecraft players on most of the game’s many platforms: the Xbox One, Windows 10, mobile, and VR versions of the game now all use the same engine and can all play together without borders. Servers and content will be accessible from any Better Together platform. Microsoft has also announced that this version of the game will be coming to the Nintendo Switch, and it, too, will be able to join in the cross-platform play.

But one major platform is being left behind: PlayStation 4. Minecraft players on the PlayStation 4 will only be able to play with other PlayStation 4 users. Not because of any technical constraint, but because Sony won’t allow it.

Speaking to Gamespot, Xbox chief Phil Spencer said Sony regards platform lock-in as a way of driving sales and “that reason [for blocking cross-platform play] is not going away.” Spencer doesn’t hold out much hope for things changing, either: “I’m never going to call anything a lost cause, but I think some of the fundamental reasons and certain scenarios—they’re not really going away.”

In June, Sony execs insisted that the company has no “profound philosophical stance” against cross-platform play, and it has permitted play between the PC and PlayStation 4. But cross-console play is clearly a sticking point. While Microsoft isn’t the first developer to cite Sony’s refusal to allow cross-platform play—Rocket League developer Psyonix and Gwent developer CD Projekt have both blamed Sony for the limitation—this is the first time the company has itself fallen foul of Sony’s restrictions. Moreover, Spencer’s comments make clear that Sony’s desire to create lock-in appears to be its overwhelming concern.

If one game could make Sony reconsider, the sheer size and popularity of Minecraft means that it’s surely the one. Better Together is a substantial update, and one can well imagine that it won’t be long before Minecraft players start to expect—and even demand—the ability to play on the same servers regardless of whether they’re using their consoles, their phones, or even their PCs. For now, however, Sony appears content to deny the users of its platform access to the larger Minecraft universe.